Nonvolatile Memory Data Reading via Localized Voltage Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing nonvolatile memory devices face challenges in accurately determining the erase or programmed state of memory cells without applying high voltages, which can disrupt the charge storage layers and threshold voltages, making it difficult to read memory cell data efficiently.
Innovation Solution
The method involves applying specific voltage combinations to control gates of memory cells, including a first voltage to the read memory cell, a second voltage to other memory cells to ensure current flow regardless of their state, and a third voltage to adjacent cells, which is lower than the second voltage, to differentiate between erase and programmed states without altering the read memory cell's state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high voltage is applied to memory cells to read data, then current flow through the cells can be detected, but the charge storage layers and threshold voltages are disrupted
Solution Approach 1:
The patent applies different voltage levels to different groups of memory cells during the read operation. Specifically, a first voltage is applied to the read memory cell, a second voltage (higher than the first) to other memory cells, and a third voltage (lower than the second but higher than the first) to adjacent memory cells. This localized differentiation of voltage application allows current detection in the read cell without applying high voltage that would disrupt the charge storage layers.
Solution Approach 2:
The patent changes the voltage parameter applied to different memory cell groups to achieve selective current flow. By adjusting the voltage levels (first voltage for read cell, second voltage for other cells, third voltage for adjacent cells), the patent enables detection of the read cell state while preventing voltage-induced disruption to the charge storage layers through controlled parameter variation.
2Productivity
If voltage is applied to adjacent memory cells at the same level as other memory cells, then current flow is ensured, but the read memory cell state may be altered
Solution Approach 1:
The patent applies a differentiated voltage level specifically to adjacent memory cells during the read operation. A third voltage is applied to adjacent memory cells, which is lower than the second voltage applied to other memory cells but higher than the first voltage applied to the read memory cell. This localized voltage differentiation ensures current flow through adjacent cells for efficient reading while preventing voltage-induced state alteration in the read memory cell.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for accurate confirmation of the memory cell's state by controlling current flow through adjacent cells using carefully selected voltage levels, ensuring reliable data reading without changing the read memory cell's state, even with varying gate lengths of control gates.
Implementation Method 1
The charges in the charge storage layer may be discharged to the bulk according to F-N (Fowler-Nordheim) tunneling
Data Source
AI summary
Methods of reading memory cell data and nonvolatile memory devices, which apply a low voltage to memory cells adjacent to a memory cell from which data may be read are provided. Methods of reading memory cell data of nonvolatile memory device include applying a first voltage to a control gate of a read memory cell from among the plurality of memory cells, applying a third voltage to control gates of memory cell adjacent to the read memory cell, and applying a second voltage to control gates of memory cells other than the read memory cell and the adjacent memory cells.